Hi Ting, What I usually do is to project my functional data to fsaverage space and then smooth and downsample to whatever resolution I want. There are different fsaverage resolution meshes, like fsaverage5 (~20k vertices) and fsaverage6 (~80k vertices). This can be achieved using standard freesurfer tools like mri_vol2surf and mri_surf2surf. Note that in this scenario, even though the data is in fsaverage space, this does not preclude individual subject analysis. The advantage of the above approach is that we can still easily perform a group analysis if we want to in the future.
The disadvantage is that we lose a little bit of the subject's native cortical geometry, which is not an issue for your proposed approach. However, I am not aware of freesurfer tools that will let you downsample an arbitrary mesh. Perhaps someone who is more intimately aware of freesurfer's tools can jump in on this. Cheers, Thomas On Mon, Nov 24, 2014 at 5:10 AM, ting xu <xutin...@gmail.com> wrote: > Hi Thomas, > > I want to analyze the data in native surface space. The functional volume > data could be register to native surface with bbregister, however, the > resolution of the native surface is quite high, too much nodes for > computational capacity to me. Any ideas? > > Thanks, > > Ting > > > On Fri, Nov 21, 2014 at 10:37 PM, Thomas Yeo <ytho...@csail.mit.edu> wrote: >> >> Hi Ting, >> >> I am not an expert, but why do you want to downsample the native >> surface mesh? The usual way of doing this is to register the full >> surface mesh with the functional volume data using Doug's bbregister. >> >> Cheers, >> Thomas >> >> On Fri, Nov 21, 2014 at 4:08 AM, ting xu <xutin...@gmail.com> wrote: >> > Dear freesurfer experts, >> > >> > Is there any way to down resample the native surface mesh and register >> > the >> > functional volume data to the down resampled surface in freesurfer? >> > >> > Many thanks, >> > >> > Ting >> > >> > >> > _______________________________________________ >> > Freesurfer mailing list >> > Freesurfer@nmr.mgh.harvard.edu >> > https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer >> > >> > >> > The information in this e-mail is intended only for the person to whom >> > it is >> > addressed. If you believe this e-mail was sent to you in error and the >> > e-mail >> > contains patient information, please contact the Partners Compliance >> > HelpLine at >> > http://www.partners.org/complianceline . If the e-mail was sent to you >> > in >> > error >> > but does not contain patient information, please contact the sender and >> > properly >> > dispose of the e-mail. >> > >> _______________________________________________ >> Freesurfer mailing list >> Freesurfer@nmr.mgh.harvard.edu >> https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer > > > _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
